<div id="left">
  
  <div id="widget_category" class="widget widget_categories">
    <h3>商品分类</h3>
    <?php //display_category_tree();?>
    <ul>
<?php foreach (get_categories_by_parent_id() as $left_category) { ?>
        <li><a href="<?php echo url('?module=category&category_id=' . $left_category['id']);?>"<?php if (isset($_GET['category_id']) && $_GET['category_id'] == $left_category['id']) {?> class="current_category"<?php }?>><?php echo $left_category['name'];?></a></li>
<?php }?>
    </ul>
  </div>
      
  <div id="widget_guestbook" class="widget widget_guestbook">
    <h3>留言簿</h3>
    <ul>
      <li><a href="<?php echo url('?module=message');?>"<?php if ($module == 'message') {?> class="current_page"<?php }?>>留言簿</a></li>
    </ul>
  </div>

  <div id="widget_page" class="widget widget_page">
    <h3>页面</h3>
    <?php //display_page_tree();?>
    <ul>
<?php foreach (get_pages_by_parent_id() as $left_page) { ?>
        <li><a href="<?php echo url('?module=page&page_id=' . $left_page['id']);?>"<?php if (isset($_GET['page_id']) && $_GET['page_id'] == $left_page['id']) {?> class="current_page"<?php }?>><?php echo $left_page['title'];?></a></li>
<?php }?>
    </ul>
  </div>

</div>